Train

ABSTRACT

The invention relates to a train ( 1 ) which forms a transport device displaceable along a fixed track ( 3 ), comprising a frame with a drive; at least one bogie ( 6 ) with a flat sole ( 10 ); and at least one supply of a liquid which is suitable for pouring the liquid over the track ( 3 ), wherein at speed of the train higher than a threshold value at least a part of the sole ( 10 ) floats over a film created by liquid. The supply is adapted to carry the liquid onto the track ( 3 ) in front of the sole ( 10 ) in the direction of movement of the train ( 1 ) and the sole ( 10 ) is positioned inclining upward on the front side in the direction of movement. The invention also relates to a track ( 3 ) for an above described train ( 1 ) which comprises at least one platform extending in horizontal direction. The platform is coated with a levelling material, wherein an upper surface of the track has a very high degree of smoothness with very small height differences.

The present invention relates to a train which forms a transport devicedisplaceable along a fixed track, comprising:

a frame with a drive;

at least one bogie with a flat sole; and

at least one supply of a liquid which is suitable for pouring the liquidover the track, wherein at a speed of the train higher than a thresholdvalue at least a part of the sole floats over a film created by theliquid.

Such a train is known from the British patent specification 5.569 inwhich such a configuration of a train is described, wherein transport ismade possible particularly as a result of the upward force of the liquidwhich is generated by a compressor and which is directed under the soleto discharge the liquid under pressure here via the supply.

According to the prior art the pressure to be generated by thiscompressor must be maintained even when an aquaplaning effect occursabove a determined speed, wherein a part of the bottom surface of thesole floats over a water film. A drawback associated herewith is that aheavy compressor is required, wherein as a result of the configurationof the prior art, too much water or another liquid is lost precisely asa consequence of the high pressure to enable transport over a distancewhich is usual in practice.

A further drawback is that the supply debouches under the sole. At ahigh speed there is the danger here that the part of the surface of thesole located at the front in the direction of movement of the train isdeprived of water or other liquid, which does not reach this front partof the surface of the sole, precisely as a result of this high speed andthereby insufficient pressure. In this situation that part of thesurface of the sole deprived of liquid will come into contact with thesurface of the track because no liquid film lies therebetween. In thissituation the train will travel in a jolting manner until the speed issufficiently reduced and the liquid under pressure can once again reachthe front part of the surface of the sole on the track. The damage whichcan hereby be caused to track and sole is considerable.

The invention has for its object to obviate at least one of the abovestated problems and a train is provided for this purpose which isdistinguished in that the supply is adapted to carry the liquid onto thetrack in front of the sole in the direction of movement of the train,and that the sole is positioned inclining upward on the front side inthe direction of movement.

In this manner is ensured that at any speed above the threshold valuethe entire sole is involved in the aquaplaning effect, wherein theentire sole slides above the track, floating on the liquid film. Furtherachieved, in combination with the form of the track, is that only a verysmall quantity of liquid is required to realize the liquid film, whereinthis liquid moreover does not have to be delivered at high pressureunder the sole but, on the contrary, can simply be deposited on thetrack practically without pressure. As already stated above, smallquantities of liquid can herein suffice to bring about the intendedeffect. The track can moreover be cleaned during application of theliquid, which is herein sprayed over the track under some pressure. Thesole is further positioned inclining upward at the front in order tobring the largest possible quantity of liquid under the sole, wherein aprogressively smaller space or volume in rearward direction isavailable, so that an equilibrium results between the force of the wateron the sole and vice versa.

In a first embodiment a train according to the present invention has theproperty that the bogie is arranged for free tilting on the train atleast in the direction of movement thereof, wherein the tilting point ofthe bogie is positioned in the direction of movement behind the centreof the length of the sole and in front of the maximum of the upwardpressure on the bogie generated at the higher speed by the liquid film.As a result of the ability of the sole to tilt freely, a self-adjustmentof the position of the sole is effected depending on the pressure on thesole and on the speed of the train. This is the case because the totalmoment acting at a determined speed on the part of the sole in front ofthe tilting point in the direction of movement is in equilibrium withthe total moment exerted on the part of the sole behind the tiltingpoint. The front part of the sole is herein directed slightly upward,wherein the tilting point is situated just behind the centre of thelength of the sole and the sole encloses a relatively thick liquid filmon the front side.

In a second embodiment a train according to the present invention hasthe property that the sole forms a sliding surface, wherein the slidingsurface preferably contains grooves lying in the direction of locomotionof the train. Thus is achieved that respectively for the sole designedas sliding surface a large support surface is provided on the water filmspread on the track and that even distribution of the water film isobtained by means of the grooves. In an embodiment of the trainaccording to the invention has the property that the grooves aredesigned narrowing in rearward direction relative to the direction oflocomotion. More of the liquid lying on the track is hereby enclosedbeneath the sliding surface and pressed out of the grooves in downwarddirection along the length of the grooves so as to have a favourableinfluence on the upward force generated by the water film.

In a third embodiment of the present invention a train according to thepresent invention has the property that at least one supplementarysupply of additional liquid is arranged in the bogie and debouches underthe sole. In this manner a per se known configuration is obtained, whichis however only used or set into operation as long as the thresholdvalue of the speed is not yet reached by the moving train. Possiblelosses can also be replenished using the supplementary supply, which isparticularly relevant when the train is one with a number ofsuccessively arranged bogies which, in respect of the liquid film, areall dependent on a collective supply at the front part of the train infront of the leading bogie.

In a fourth embodiment a train according to the present invention hasthe property that at least one conduit is arranged in the bogie whichdebouches under the sole for supply of a fluid with a lower viscositythan the liquid. Use can herein be made of for instance gas as fluid,wherein as a result of supplying this fluid with a lower viscosity thanthe liquid the aquaplaning effect is better utilized, wherein the solefloats over the liquid with the fluid thereon on the track, so that themovement resistance is decreased. The fluid therefore preferably alsohas a lower density, so that is remains lying on the liquid, thisalready being ensured particularly when gas is used as fluid.

In a fifth embodiment a train according to the present invention has theproperty that the sole is divided into at least two areas which areenclosed by downward extending peripheries of resilient materialsubstantially along the circumference of each of the areas. Inpreference each of the two areas can be separately provided herein withliquid and optionally fluid, so that control of the position of the solein lateral direction, in the direction of locomotion of the train orboth can be hereby obtained or improved, so that adjustment of thisposition can be optimized subject to the speed under the influence of anactive control. The peripheries manufactured of resilient material areprovided to minimize losses, whereby as much of the supplied liquid andthe supplied fluid as possible can be used efficiently without flowingdirectly out of the space under the sole, whereby losses occur.

The invention otherwise also relates to a track for a train according toany of the foregoing claims which comprises at least one platformextending in horizontal direction. This track is also known from theabove mentioned publication of the British patent specification 5.569,wherein this track results in considerable losses as a result of theinherent properties thereof, and particularly the deficient smoothnessthereof.

A track according to the present invention is distinguished in that theplatform is coated with a levelling material, wherein an upper surfaceof the track has a very high degree of smoothness with very small heightdifferences. As a result of the properties of the track provided hereaccording to the invention, losses as a result of unevenness areminimized. In order to obtain the desired smoothness or evenness use canpreferably be made of ultra high molecular weight polyethylene, withwhich a very high degree of evenness can be realized.

In a first embodiment a track according to the present invention has theproperty that a guide extending in upward direction is arranged alongthe longitudinal axis of the track, which guide comprises engaging meanson at least one side for co-action with the drive of the train. Becausethe guide extends along the longitudinal axis of the track, engagementfor the purpose of driving takes place at least close to the centre ofthe track, so that a possible asymmetrical distribution of forces andpitching sideways of the train as a result thereof is prevented ineffective manner.

As a possible second embodiment, the engaging means preferably compriseat least one gear rack path, wherein the drive comprises at least onetoothed wheel co-acting with the gear rack path and connected to amotor. This is therefore an embodiment which is simple of realization,entails relatively low cost and which preferably comprises a two-sidedcentral drive. Alternatively, it is possible within the scope of thisembodiment that a guide extending in upward direction is arranged alongthe longitudinal axis of the track and that the track or the guidecomprises means co-acting with a contact-free driving of the train, suchas a magnetic drive. It is obvious that the drive for reaching andmaintaining the speed required for aquaplaning can be realized in manyways.

In a third embodiment a track according to the present invention ischaracterized by at least one supply of liquid connectable to a bogie ofthe train. The supply of liquid has the advantage that in order to bemoved the train itself does not have to be provided with a tank orsimilar means other than for instance an emergency tank from whichliquid can be drawn in the case that the supply in the track provides noor insufficient liquid.

The same applies in a fourth embodiment of a track according to theinvention which is characterized by at least one conduit of fluidconnectable to a bogie of the train or by power conductors connectableto the train for transport of electrical power to the train. In thelatter case the need for an overhead line is dispensed with.

The invention will be further elucidated hereinbelow with reference toan embodiment thereof. In the drawing:

FIG. 1 shows a partly cut-away perspective view of a train and trackaccording to the present invention;

FIG. 2 shows a partly cut-away perspective view of a detail of the trainshown in FIG. 1;

FIG. 3 shows a side-view in cross-section along a line III—III in FIG. 2of a detail therein;

FIG. 4 is a schematic view of the principle of operation of theinvention;

FIG. 5 shows a perspective view of a detail of FIG. 1; and

FIG. 6 shows a detail of the slider shown in FIG. 5.

Corresponding components are designated in the figures with the samereference numerals.

The train 1 shown in FIG. 1 comprises a number of bogies 6 which will befurther described hereinbelow, coachwork 2 and partitions 4 on the sideof train 1. Train 1 travels over a track 3 which is provided for thispurpose with a coating 7 at the location of bogies 6 and sliders 24,which are positioned in line in the direction of locomotion. The trackfurther comprises a guide designed as a ridge 5 on which is arranged agear rack path 15 which is engaged by a toothed wheel 16, which toothedwheel forms part of the drive of the train, of which a motor (not shown)such as an electric motor also forms part. Alternatively (not shownhere), use can be made of for instance a magnetic drive or other type ofsuitable drive instead of the mechanical drive by means of the gear rackpath and driven toothed wheel co-acting therewith.

In the embodiment shown here, track coating 7 is manufactured fromUHMWPE, or ultra high molecular weight polyethylene, which is flexibleto some extent and displays very specific and advantageous properties inrespect of the smoothness to be realized therewith of the surface oftrack 3 over which bogies 6 move. UHMWPE moreover has the capacity toabsorb dust and dirt into itself under the influence of sufficientpressure, so that these cannot have a disrupting influence on theaquaplaning effect. Track 3 otherwise has a very small downwardinclination, in the order of magnitude of 1:100-1:500, laterally in bothdirections from the centre formed by ridge 5.

Scraping devices can be arranged as possible addition to the embodimentshown in FIG. 1. These can be designed for instance in a <> or a ><configuration at a position between spray nozzles and first bogie orslider or in front of the spray nozzles. Such a scraping device canfurther have a configuration with one or more than one pressure edge onthe basis of the principle of a pressure collar shown for instance inFIG. 3.

With reference to FIG. 2 it is noted that the bogie 6 shown here ismounted by means of a shaft 14 on a leg 12, wherein bogie 6 is tiltableup and/or downward in the travel direction of the train relative to leg12 and therefore relative to the other parts of the train, such asprofile 13, this being indicated with dotted line 25. In the embodimentshown here, bogie 6 is also tiltable in lateral direction by means of atilting connection between shaft 14 and leg 12, whereby adapting of theposition of bogie 6, and therefore of sole 10 thereof, transversely oftravel direction A is possible, which results for instance in a bettertrack-holding of the bogie when a bend must be negotiated and the trackhere has a certain inclination corresponding with the bend. The bogiewith sole 10 thereon is therefore preferably tiltable in all directions.The sole further has dimensions of 0.5×0.5 m, which is only an example.The shape of sole 10 shown here, and therefore of bogie 6, also hasalternatives within the scope of the present invention. In an embodiment(not shown) use can thus be made of a sole with a triangular shape, or apart of an ellipse, although other shapes are also possible. The same istrue of sliders 24 in FIG. 1.

The leg 12 can be provided in a random known manner with a damping orsuspension to prevent jolts occurring during movement of the train.

A supplementary supply of additional liquid designed as supply 8 runsthough profile 13, wherein in this case the liquid is water. A conduitdesigned as gas supply 9 for supplying a fluid with a lower viscositythan the liquid is further also arranged in profile 13. Each watersupply 8 in particular runs to an atomizing spray nozzle 23 with whichdirt is sprayed from track 3 and liquid (water) is sprayed onto thetrack.

Water supply 8 and gas supply 9 are each connected by means of waterhoses 18 and gas hoses 17 respectively to a number of sub-sectors ofsole 10 designed as compartments 11. FIG. 2 shows schematically thatpressure regulators 19 are arranged in water hoses 18 and gas hoses 17to control the supply of gas and water to each of the compartments 11.It is possible for pressure regulators 19 for a number of bogies 6 to becollectively controlled so as to realize uniformity of the position ofthe bogies relative to the underside of train 1 and to the track 3 forthese bogies 6.

In the embodiment shown in FIG. 2, the compartments are each providedwith individually controllable pressure collars 27 such as will befurther described with reference to FIG. 3. In an alternative embodiment(not shown) it is however equally possible within the scope of thepresent invention to apply a single pressure collar which encloses allthe compartments 11, wherein a single separation is arranged between thecompartments. A bogie 6 can also be designed such that it comprises asingle compartment with a single pressure collar therearound, whereinthis latter, whether or not it makes an essential contribution to thebearing capacity, serves to maintain and provide replenishment to thewater film over which the sliders can then float. In the configurationof FIG. 2 it is possible to control the operation of sole 10 percompartment 11 via gas hoses 17 and water hoses 18 and also via pressurecollars 27, the operation of which can be controlled per compartment 11.

During use a layer of gas will spread over the water so that, as aresult of the lower viscosity and the lower “drag coefficient” ormovement resistance associated herewith, a greater efficiency isobtained. If use is made not of gas but a second liquid with a lowerviscosity, this second liquid must have a lower density so that it formsa layer on the layer of the first liquid. In the embodiment shown herethe sole 10 is further designed as a stainless steel plate covered witha rubber layer, wherein the rubber layer, the UHMWPE layer 7 on track 3and the water film and gas layer therebetween co-act as a result of inany case the flexibility of the rubber layer and the UHMWPE layer tobring about micro-adjustment, i.e. irregularities of small dimensions donot have any influence on the aquaplaning effect.

FIG. 3 is a view in cross-section of a detail of FIG. 2 designated withthe line III—III of the pressure collar 27 shown therein.

Pressure collar 27 is formed here by a form-retaining profile 30 withcavities opened to the bottom. Elastically expandable bodies 28 arearranged in these cavities, wherein however the central cavity 29 isempty. Bodies 28 expand under the influence of pressure which is exertedthereon by means of conduits 31 and which can be created pneumaticallyor hydraulically. In the embodiment shown here, conduits 31 are suitablefor supply of liquid under pressure, as is the conduit 32 leading tocentral cavity 29. When the train starts, the elastically expandablebodies 28 are placed under pressure so as to expand, wherein a waterpressure is then generated in central cavity 29, wherein this pressurehas a value greater than or equal to the pressure generated in theelastically expandable bodies 28. The underside of each of theelastically expandable bodies 28 is hereby pressed onto track 7, whilefrom central cavity 29 a thin water film is urged beneath theelastically expandable bodies 28. A thin film of water from centralcavity 29 hereby reaches the outside of pressure collar 27, so thatbogie 6 with sole 10 thereon with pressure collar 27 is raised underpressure collar 27 and a thin water film is provided for the sliders 24shown in FIG. 1 and further described hereinbelow with reference to FIG.5. From stationary position a pressure of for instance 8 bar is hereingenerated in the elastically expandable bodies 28 and an at leastslightly higher pressure, for instance 8.1 bar, is generated in thecentral cavity 29 so that the water will spread in all directionsrelative to central cavity 29. At pressures such as mentioned above,each bogie as according to FIGS. 2 and 3 is capable of carrying a weightof ±20 tons. Since an average carriage has a weight of about 80 tons,four bogies per carriage are sufficient to lift this one carriage.

The elastically expandable bodies 28 otherwise have the advantage thatthe underside of the bogie optimally adapts at all times toirregularities possibly present in the surface of track 7.

By adapting the pressure in the elastically expandable bodies 28, incentral cavity 29 and the space under the bogie where gas hose 17 andwater hoses 18 debouch, it is possible to influence the behaviour of thebogie in respect of the water film generated therewith as well as thetilting behaviour and the tilting position of the bogie. In this mannera very readily applicable solution is therefore provided, inter alia asa result of the small water losses, which results in an efficientlyoperating train.

FIG. 4 shows the operating principle of a bogie or, more particularly,of a slider 24 as shown in FIG. 1 which will be further describedhereinbelow with reference to FIG. 5, in a train according to thepresent invention. Sole 10 or sliding surface 33 is shown herein as aplate 20 and the shaft is shown as the component 21 designed as tiltingpoint.

In this figure a curve is also plotted indicating the upward pressure onthe underside of the sole or the sliding surface exerted by the waterfilm. This curve is designated with 22.

The tilting point 21 is placed eccentrically relative to sole 20 orsliding surface 33, i.e. tilting point 21 is situated behind the centreof the length of plate 20, as viewed in the direction of locomotion ofthe train designated with arrow A.

Curve 22 shows that the upward pressure exerted on the underside ofplate 20 increases in rearward direction at a determined speed as aresult of the inclining position of plate 20 until it reaches a maximumclose to the rear of the plate, and then decreases to zero over a shortdistance along plate 20. This decrease from the maximum to zero over therear part of plate 20 can be attributed to a suction action close to therear end of the plate 20 on the liquid, more particularly the water,thereunder.

The inclining position of plate 20 ensures that all the water oroptionally other liquid arranged on the track is enclosed beneath plate20. Plate 20 subsequently moves thereover, wherein the sloping positionthereof inclining upward at the front is maintained. This latter is aresult of the fact that the moment generated in front of tilting point21 in the direction of movement is in equilibrium with the momentgenerated behind tilting point 21 in the direction of movement.

When plate 20 moves over the water film, the water film is compressedthereunder in the rearward direction of the sole, which results in themaximum in curve 22.

At a change in the speed of the train, a shift of the maximum in curve22 would be caused in the case of a fixed position of the sole orsliding surface. However, in the embodiment shown here, the sole ismounted for tilting in the bogie at the tilting point 21. As a resulthereof, under the influence of the tendency of the maximum to shift at avariation in the speed of the train, it is the position of sole 20 orsliding surface 33 which will change in order to prevent a shift of themaximum in curve 22 and a change in the equilibrium. Plate 20 istherefore self-adjusting in respect of the pressure on the sole and/orthe speed of the train in the direction of the arrow A.

FIG. 5 shows a perspective view of a slider 24 as applied in the trainshown in FIG. 1. FIG. 6 further shows a detail of slider 24 shown inFIG. 5. Slider 24 is connected to the train in the same manner as bogie6 in FIG. 2 and is therefore also self-adjusting in respect of the speedof the train in the direction of the arrow A which is also shown here,as described with reference to FIG. 4. Said connection is here also suchthat slider 24 is tiltable in the direction parallel to the direction ofmovement of arrow A and the direction transversely hereof, so thatslider 24 can be placed in any random tilting position relative to thehorizontal within pre-determined ranges, which takes place mainly underthe influence of the upward pressure exerted thereon by the liquid overwhich slider 24 moves.

As is shown most clearly in FIG. 6, sliding surface 33 of slider 34 isprovided on the underside with profiled grooves which have a convergingform in a direction opposed to the direction of movement of arrow A. Thegrooves are designated with reference numeral 34. This brings about animproved containment of the water film lying on track 7 under slidingsurface 33 at the front in the direction of movement of arrow A, thuspreventing a part of this water film on track 7 being scraped off by thefront edge of sliding surface 33. This would result in a reduction ofthe aquaplaning effect, which is therefore effectively prevented.

The water enclosed in the wide part 35 of grooves 34 is compressed inrearward direction, when slider 24 moves thereover, as a result of theconvergence of grooves 34. Owing to this compressing action of grooves34 the water is also driven out of these grooves 34 in downwarddirection, thus bringing about an improvement in the pressure of thewater film over track 7 in upward direction on slider 24.

The depiction of the grooves in FIGS. 5 and 6 is slightly exaggerated.In a practical embodiment they are markedly smaller but are shown hereenlarged for the sake of clarity. The form of the grooves in anembodiment not shown here is also such that the depth thereof decreasesto zero in rearward direction relative to the direction of locomotion ofthe train. In another embodiment (not shown) the form of the grooves isnot parallel to the direction of locomotion but herringbone-shaped,wherein the grooves run in rearward direction from the sides of theslider to the middle of the slider and herein may or may not decrease indepth to zero.

Particularly when use is made of the scraping device(s) such asdescribed with reference to FIG. 1, the groove patterns under thesliders can possibly by dispensed with, since with the scrapingdevice(s) a distribution of the water film over desired parts of thesurface of track 7 can be achieved to allow each of the sliders tofunction.

In an embodiment (not shown) use is made instead of these grooves of forinstance a chamfering of the leading edge of the sliding surface inorder to prevent a part of the water film being scraped off hereby. Manyother embodiments are further possible within the scope of the inventionas defined in the appended claims, such as a triangular shape or theshape of a semi-ellipse for the bogie or the slider, a different choiceof material for the track, as long as this material can be applied inhard and flat manner, chamferings on the sliders etc., so that the scopeof protection of the appended claims should not be interpreted as beinglimited to the above described embodiments.

What is claimed is:
 1. Train which forms a transport device displaceablealong a fixed track, comprising: a frame with a drive; at least onebogie with a flat sole; and at least one supply of a liquid which issuitable for pouring the liquid over the track, wherein a speed of thetrain higher than a threshold value at least a part of the sole floatsover a film created by the liquid, characterized in that the supply isadapted to carry the liquid onto the track in front of the sole in adirection of movement of the train, and that the sole is positionedinclining upward on a front side in the direction of movement.
 2. Trainas claimed in claim 1, characterized in that the bogie is arranged forfree tilting on the train at least in the direction of movement thereof,wherein a tilting point of the bogie is positioned in the direction ofmovement behind a center of the length of the sole and in front of amaximum the upward pressure on the bogie generated at the higher speedby the liquid film.
 3. Train as claimed in claim 1, characterized inthat the sole forms a sliding surface.
 4. Train as claimed in claim 3,characterized in that the sliding surface contains grooves lying in adirection of locomotion of the train.
 5. Train as claimed in claim 4,characterized in that the grooves are designed narrowing in rearwarddirection relative to the direction of locomotion.
 6. Train as claimedin claim 1, characterized in that at least one supplementary supply ofadditional liquid is arranged in the bogie and debouches under the sole.7. Train as claimed in claim 6, characterized in that at least oneconduit is arranged in the bogie which debouches under the sole forsupply of a fluid with a lower viscosity than the liquid.
 8. Train asclaimed in claim 6, characterized in that the sole is divided into atleast two areas which are enclosed by downward extending peripheries ofresilient material substantially along the circumference of each of theareas.